I think lots of users have the same problem - tons of emails from JIRA. Emails number can be lowered by different notification scheme, but the point is to have different levels of notifications in JIRA - the first one, for which action is required (assigning of issue to you or direct mentioning), and the second one - all other updates.
One way which can be used for this - filter emails (for example with Gmail filters functionality).
For mention notifications, we have notifications with different topic with "mentioned you" inside, which is convenient to filter.
But for assigning notification - the same topic as for other updates is used. Also, if you watch ticket, you don't get separate mention notification.
Any suggestion - for both Server/Cloud, or with usage of some plugin, are appreciated!
Many thanks in advance!